Induction of colonic regulatory T cells by indigenous Clostridium species

Role of insulinemic and inflammatory dietary patterns on gut microbial composition and circulating biomarkers of metabolic health among older American men

Chronic low-grade inflammation and hyperinsulinemia are linked with metabolic dysfunction and dysbiosis. This study investigated the role of dietary inflammatory and insulinemic potential on gut microbiome and circulating health biomarkers in older men. Data from the Osteoporotic Fractures in Men (MrOS) study were analyzed. Reversed Empirical Dietary Inflammatory Pattern (rEDIP), Empirical Dietary Index for Hyperinsulinemia (rEDIH), and Healthy Eating Index (HEI)-2020 scores were computed from food frequency questionnaire data. Stool samples were profiled using 16S rRNA sequencing. Elastic net regression identified diet-associated microbial profiles and multivariable-adjusted linear regression assessed diet-biomarker associations. Higher rEDIP, rEDIH, and HEI-2020 scores were positively associated with gut microbiota alpha diversity. Specific genera, including Intestinibacter and Lachnospira, associated positively, while Dielma, Peptococcus, Feacalitalea, and Negativibaccilus associated inversely with healthier dietary patterns. When evaluating changes in dietary patterns between baseline and visit 4 ( ~ 14 years), these genera tended to define rEDIP, rEDIH more than HEI-2020. In addition, higher dietary quality was linked to better biomarker profiles, including lower creatinine, sodium, triglycerides, and insulin resistance. Beneficial effects of higher dietary quality on health may be mediated by the ability of diet to regulate gut microbial composition and metabolic biomarker profiles.

Precision microbiota therapy for IBD: premise and promise

Inflammatory Bowel Disease (IBD) is a spectrum of chronic inflammatory diseases of the intestine that includes subtypes of ulcerative colitis (UC) and Crohn's Disease (CD) and currently has no cure. While IBD results from a complex interplay between genetic, environmental, and immunological factors, sequencing advances over the last 10-15 years revealed signature changes in gut microbiota that contribute to the pathogenesis of IBD. These findings highlight IBD as a disease target for microbiome-based therapies, with the potential to treat the underlying microbial pathogenesis and provide adjuvant therapy to the emerging spectrum of advanced therapies for IBD. Building on the success of fecal microbiota transplantation (FMT) for Clostridioides difficile infection, therapies targeting gut microbiota have emerged as promising approaches for treating IBD; however, unique aspects of IBD pathogenesis highlight the need for more precision in the approach to microbiome therapeutics that leverage aspects of recipient and donor selection, diet and xenobiotics, and strain-specific interactions to enhance the efficacy and safety of IBD therapy. This review focuses on both pre-clinical and clinical studies that support the premise for microbial therapeutics for IBD and aims to provide a framework for the development of precision microbiome therapeutics to optimize clinical outcomes for patients with IBD.

Post sleeve gastrectomy-enriched gut commensal Clostridia promotes secondary bile acid increase and weight loss

The gut microbiome is altered after bariatric surgery and is associated with weight loss. However, the commensal bacteria involved and the underlying mechanism remain to be determined. We performed shotgun metagenomic sequencing in obese subjects before and longitudinally after sleeve gastrectomy (SG), and found a significant enrichment in microbial species in Clostridia and bile acid metabolizing genes after SG treatment. Bile acid profiling further revealed decreased primary bile acids (PBAs) and increased conjugated secondary bile acids (C-SBAs) after SG. Specifically, glycodeoxycholic acid (GDCA) and taurodeoxycholic acid (TDCA) were increased at different follow-ups after SG, and were associated with the increased abundance of Clostridia and body weight reduction. Fecal microbiome transplantation with post-SG feces increased SBA levels, and alleviated body weight gain in the recipient mice. Furthermore, both Clostridia-enriched spore-forming bacteria and GDCA supplementation increased the expression of genes responsible for lipolysis and fatty acid oxidation in adipose tissue and reduced adiposity via Takeda G-protein-coupled receptor 5 (TGR5) signaling. Our findings reveal post-SG gut microbiome and C-SBAs as contributory to SG-induced weight loss, in part via TGR5 signaling, and suggest SBA-producing gut microbes as a potential therapeutic target for obesity intervention.

Translating animal models of SARS-CoV-2 infection to vascular, neurological and gastrointestinal manifestations of COVID-19

Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) initiated a global pandemic resulting in an estimated 775 million infections with over 7 million deaths, it has become evident that COVID-19 is not solely a pulmonary disease. Emerging evidence has shown that, in a subset of patients, certain symptoms - including chest pain, stroke, anosmia, dysgeusia, diarrhea and abdominal pain - all indicate a role of vascular, neurological and gastrointestinal (GI) pathology in the disease process. Many of these disease processes persist long after the acute disease has been resolved, resulting in 'long COVID' or post-acute sequelae of COVID-19 (PASC). The molecular mechanisms underlying the acute and systemic conditions associated with COVID-19 remain incompletely defined. Appropriate animal models provide a method of understanding underlying disease mechanisms at the system level through the study of disease progression, tissue pathology, immune system response to the pathogen and behavioral responses. However, very few studies have addressed PASC and whether existing models hold promise for studying this challenging problem. Here, we review the current literature on cardiovascular, neurological and GI pathobiology caused by COVID-19 in patients, along with established animal models of the acute disease manifestations and their prospects for use in PASC studies. Our aim is to provide guidance for the selection of appropriate models in order to recapitulate certain aspects of the disease to enhance the translatability of mechanistic studies.

Immunosuppressant imprecision: multidirectional effects on metabolism and microbiome

SUMMARYTransplant recipients require lifelong, multimodal immunosuppression to prevent rejection by dampening alloreactive immunity. These treatments have long been known to lack antigen specificity. Despite empirically selected long-term immunosuppression regimens, most allografts succumb to alloimmune responses that result in chronic inflammation and scarring. Additionally, immunosuppressive medications themselves contribute to unintended intestinal dysbiosis and metabolic disorders. This review focuses on the effect of immunosuppressant treatments on alloimmunity, gut microbiome, and metabolism, with a particular emphasis on the effects on metabolic disorders. We also outline the shared and unique microbial and metabolic signatures produced by each immunosuppressant class, underlining their distinct impacts on immunity and metabolic homeostasis. These observations underscore the need for a holistic understanding of these drugs' on- and off-target effects to refine therapeutic strategies, enhance immunosuppression efficacy, and ultimately enhance graft and patient survival. By characterizing these complex interactions, strategies informed by the gut microbiome and host metabolism may offer a promising adjunctive approach to optimizing immunosuppressive regimens and promoting sustained graft acceptance.

Dysbiosis of the gut microbiome may contribute to the pathogenesis of oral lichen planus through Treg dysregulation

Oral lichen planus (OLP) is a chronic inflammatory disorder with autoimmune features and malignant transformation risk, lacking a definitive treatment, with CD4+ T cells being pivotal in its pathogenesis. Dysbiosis, an imbalance in the microbiome, is linked to various autoimmune and inflammatory diseases, where CD4+ T cells play a significant role. Given these insights, the development of OLP might be influenced by dysbiosis. This study investigates the association between dysbiosis and CD4+ T cells in OLP. We collected stool and saliva samples from OLP patients, conducting 16S rRNA gene analysis and mass spectrometry, and assessed CD4+ T cell characteristics in lesions through multiplex immunofluorescence and single-cell RNA sequencing. Peripheral blood samples were subjected to flow cytometry and cell culture assays. Results showed extensive gut dysbiosis in OLP patients, notably a reduction in short-chain fatty acid (SCFA)-producing bacteria essential for regulatory T cell (Treg) differentiation. While various CD4+ T cell subsets, including Tregs, were present in tissues, these Tregs as unresponsive to specific antigens, showing reduced immunosuppressive molecule expression. The decline in SCFA-producing bacteria correlated with fewer activated Tregs in tissues and blood. These findings suggest that gut dysbiosis may contribute to OLP by impairing Treg regulation, influencing disease pathogenesis.

Designing live bacterial therapeutics for cancer

Humans are home to a diverse community of bacteria, many of which form symbiotic relationships with their host. Notably, tumors can also harbor their own unique bacterial populations that can influence tumor growth and progression. These bacteria, which selectively colonize hypoxic and acidic tumor microenvironments, present a novel therapeutic strategy to combat cancer. Advancements in synthetic biology enable us to safely and efficiently program therapeutic drug production in bacteria, further enhancing their potential. This review provides a comprehensive guide to utilizing bacteria for cancer treatment. We discuss key considerations for selecting bacterial strains, emphasizing their colonization efficiency, the delicate balance between safety and anti-tumor efficacy, and the availability of tools for genetic engineering. We also delve into strategies for precise spatiotemporal control of drug delivery to minimize adverse effects and maximize therapeutic impact, exploring recent examples of engineered bacteria designed to combat tumors. Finally, we address the underlying challenges and future prospects of bacterial cancer therapy. This review underscores the versatility of bacterial therapies and outlines strategies to fully harness their potential in the fight against cancer.

Role and mechanism of gut microbiota-host interactions in the pathogenesis of Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic, nonspecific inflammatory bowel disease with a poor prognosis. Despite its increasing incidence, curing CD remains challenging due to its complex etiology and unclear pathogenesis.

METHODS

A comprehensive PubMed and Web of Science search was conducted using the keywords Crohn's disease, gut microbiota, dysbiosis, pathogenesis and treatment, focusing on studies published between 2014 and 2024.

RESULTS

Recent studies have demonstrated a close relationship between gut microbiota dysbiosis and the development of CD. Although many dysbioses associated with CD have not yet been proven to be causal or consequential, it has been observed that the gut microbiota in CD patients exhibits reduced diversity, a decrease in beneficial bacteria, and an increase in pathogenic bacteria. These changes may lead to decreased intestinal barrier function, abnormal immune responses, and enhanced inflammatory reactions, which are related to the disease's activity, phenotype, drug treatment efficacy, and postoperative therapeutic outcomes. Therefore, further exploration of the microbiota-host interactions and the pathogenesis of CD, the identification of biomarkers, and the development of targeted strategies for modulating the gut microbiota could offer new avenues for the prevention and treatment of CD.

CONCLUSIONS

This review highlights the pivotal role of gut microbiota dysbiosis in driving CD pathogenesis and its progression, while underscoring its potential as a therapeutic target through dietary modulation, microbial interventions, and integrative strategies to improve clinical management and prognostic outcomes.

Integrated faecal microbiota and blood metabolic changes following different dietary zinc oxide levels in weaned piglets

This study investigated faecal microbial composition and blood metabolome profile of piglets fed different levels of supplementary zinc oxide (ZnO) after weaning. A dose-response study was conducted with four experimental diets containing 153 (D153), 1022 (D1022), 1601 (D1601), and 2407 (D2407) ppm zinc (Zn) in the feed. At the end of the trial, blood and faeces samples were obtained for analyses. Multivariate analysis of the blood metabolomics dataset and Principal Coordinate Analysis (PCoA) of faecal microbiota data showed that pigs receiving D2407 had a different metabolic and microbial profile to the other groups, whereas no differences were observed in pigs fed with D153, D1022, and D1601. The highest dietary Zn inclusion was associated with significant increase in the abundance of Clostridium sensu stricto, Terrisporobacter, Dorea, and Prevotellaceae_NK3B31_group and a decrease in relative abundances of Methanobrevibacter, Treponema, Megasphaera, and UCG 002 genera. Pearson's correlation analysis showed positive correlations between the abundance of Christensenellaceae R7-group with amino acids metabolism and production of microbial metabolites. The results suggest that only 2407 ppm Zn altered gut microbiota and modulated blood metabolic profile, which may impact the health status of piglets through specific microbial metabolites.

High-fertility sows reshape gut microbiota: the rise of serotonin-related bacteria and its impact on sustaining reproductive performance

BACKGROUND

Compelling evidence has established a strong link between the gut microbiota and host reproductive health. However, the specific regulatory roles of individual bacterial species on reproductive performance are not well-understood. In the present study, Jinhua sows with varying reproductive performances under the same diet and management conditions were selected to explore potential mechanisms on the intricate relationship between the gut microbiome and host reproductive performance using 16S rRNA sequencing, metagenomics and serum metabolomics.

RESULTS

Our findings revealed that the KEGG pathways for base excision repair and DNA replication were enriched, along with gene-level enhancements in spore formation, in sows with higher reproductive performance, indicating that the gut microbiome experiences stress. Further analysis showed a positive correlation between these changes and litter size, indicating that the host acts as a stressor, reshaping the microbiome. This adaptation allows the intestinal microbes in sows with high reproductive performance to enrich specific serotonin-related bacteria, such as Oxalobacter formigenes, Ruminococcus sp. CAG 382, Clostridium leptum, and Clostridium botulinum. Subsequently, the enriched microbiota may promote host serotonin production, which is positively correlated with reproductive performance in our study, known to regulate follicle survival and oocyte maturation.

CONCLUSION

Our study provides a theoretical basis for understanding the interactions between gut microbes and the host. It highlights new insights into reassembling gut microbiota in sows with higher litter sizes and the role of serotonin-related microbiota and serotonin in fertility.

Comparative genome analysis of the immunomodulatory ability of Lactiplantibacillus plantarum and Lactiplantibacillus pentosus from Japanese pickles

Lactic acid bacteria (LAB) are pivotal in food preservation and exhibit immunomodulatory effects on interleukin-10 (IL-10) and interleukin-12 (IL-12) production. Lactiplantibacillus plantarum (L. plantarum) and Lactiplantibacillus pentosus (L. pentosus) from fermented food are known for their effect; however, a comprehensive comparative genome analysis is needed to identify the linked genes. Here, we investigated the immunomodulatory capability at the genome level of L. plantarum and L. pentosus strains isolated from Japanese pickles at the genome level, and we further identified their immunomodulation-associated genes using the potential-gene (PG) index derived from the Calinski-Harabasz (CH) index. The results revealed an immunostimulatory clade with strain-specific IL-10 and IL-12 induction and identified key genes via the PG index. Both genes across two species were shown to encode the enzyme TagF2, which is crucial for synthesizing poly-glycerol-3-phosphate type wall teichoic acid (poly-GroP WTA), indicating that TagF2 plays a potential role as an effective microbe-associated-molecular-pattern. In vivo analyses confirmed the IL-10-inducing ability of one strain, reinforcing the IL-10-stimulating capacity of its poly-GroP WTA. Subpotential genes in L. plantarum TagF2-possessing strains were linked to host‒cell interactions, suggesting that such strains play potential probiotic roles. Collectively, the PG index effectively identified immunomodulation-related genes, thus paving the way for the use of the PG index to detect potential health benefit-associated genes in other LAB species.

IMPORTANCE

Lactic acid bacteria are pivotal in food preservation and exhibit immunomodulatory effects on interleukin-10 (IL-10) and interleukin-12 (IL-12) production. Lactiplantibacillus plantarum and Lactiplantibacillus pentosus from fermented food are known for such effect, yet comprehensive comparative genome analysis is needed to elucidate the linked genes of the two species. The significance of our research is in observing the immunostimulatory clade with strain-specific cytokine induction and identifying key immunostimulation-related genes encoding enzymes that are crucial for synthesizing a potentially effective microbe-associated-molecular-pattern using the potential-gene index across two species. The further in vivo validation reinforced the interleukin-10-stimulating capacity of the identified pattern, and the detected sub-potential genes in Lactiplantibacillus plantarum key-gene possessing strains implied the utility of potential-gene index in detecting potential health-benefit-associated genes in other lactic acid bacteria species.

The potential effect of gut microbiota on the secretion of selected cytokines by human cells in vitro

Colonization of the gut early in life plays a significant role in guiding the development of the immune system. The effect of individual intestinal bacterial strains on the asthma development is the subject of numerous scientific studies. The aim of the study was to determine the role and the potential mechanism of action of intestinal microflora on secretion of cytokines and potential predisposition to asthma development. The effect of Parabacteroides distasonis (PD), Bacteroides vulgatus (BV) Clostridium perfringens (CP) and Ruminococcus albus (RA) lysates on the secretion of IL-4, IL-5, IL-8 (CXCL8) and IL-13 in human peripheral blood mononuclear cells, monocytes and HT-29 cells has been analyzed by enzyme-linked immunosorbent assays. RA and PD 400 µg lysates significantly increased secretion of IL-5 by PBMC compared to control (p < 0.05). In addition, BV, CP, PD and RA 100 µg lysates significantly increased IL-8 secretion by PBMC, as well as BV, PD and RA 100 µg lysates by monocytes compared to control (p < 0.05). Moreover, PD 100 µg and 400 µg lysates significantly increased secretion of IL-8 by HT-29 cells compared to BV 100 µg and 400 µg lysates (p < 0.05). CP, BV, PD and RA 100 µg lysates significantly lowered IL-13 secretion by PBMC vs. control (p < 0.001). For a better understanding of the mechanisms of action of gut microflora and their impact on parameters important in asthma, complex studies which compare the asthma and control samples should be carried out in the future.

High-fat diet-induced osteoporosis in mice under hypoxic conditions

In the context of global aging, osteoporosis has emerged as a significant public health concern, with a relatively high prevalence observed in plateau regions. This study aimed to investigate the effects and underlying mechanisms of high-fat diet (HFD) and hypoxic conditions on bone metabolism in mice. The mice were subjected to different dietary regimens (a HFD versus a normal diet) and placed in a hypoxic environment. This study explored relevant mechanisms through comprehensive assessments, including body and bone morphological indices, pathological examinations, biochemical analyses, evaluation of gut microbiota diversity, and metabolomics approaches. The results indicated that, compared with those in the control group, the body weight, Lee's index, body mass index (BMI), and body fat percentage of the HFD-fed group were significantly greater. Additionally, the femoral microstructure was compromised, bone metabolic markers were disrupted, inflammatory responses were heightened, gut microbiota diversity was altered, and specific intestinal metabolites such as Anserine were downregulated, whereas L-carnosine was upregulated. Spearman correlation analysis and network visualization elucidated the multifactorial influence mechanism of a HFD on bone metabolism under hypoxic conditions. These factors interconnect to form a complex network that drives osteoporosis development. Notably, L-carnosine occupies a central position within this network, serving as a key hub for interactions among various factors. Under the dual stressors of hypoxia and a HFD, this network becomes imbalanced, leading to bone metabolic disorders and osteoporosis. This study provides insights into the multifactorial mechanisms of osteoporosis induced by a HFD and hypoxia in mice, offering a foundation for subsequent research and preventive strategies for osteoporosis in plateau areas.

The mechanism of disease progression by aging and age-related gut dysbiosis in multiple sclerosis

Multiple sclerosis (MS) is the most common demyelinating disease caused by a multifaceted interplay of genetic predispositions and environmental factors. Most patients initially experience the relapsing-remitting form of the disease (RRMS), which is characterized by episodes of neurological deficits followed by periods of symptom resolution. However, over time, many individuals with RRMS advance to a progressive form of the disease, known as secondary progressive MS (SPMS), marked by a gradual worsening of symptoms without periods of remission. The mechanisms underlying this transition remain largely unclear, and current disease-modifying therapies (DMTs) are partially effective in treating SPMS. Age is widely acknowledged as a risk factor for the transition from RRMS to SPMS. One factor associated with aging that may influence the progression of MS is gut dysbiosis. This review discusses how aging and age-related gut dysbiosis affect the progression of MS.

Persistent reduction of Bifidobacterium longum in the infant gut microbiome in the first year of age following intrapartum penicillin prophylaxis for maternal GBS colonization

Introduction

Group B Streptococcus is a significant cause of early-onset disease in term newborns, with a global incidence of 0.41/1000 live births. Intrapartum antibiotic prophylaxis (IAP) has reduced EOD incidence by over 80%, but concerns exist about its impact on the neonatal gut microbiome and potential long-term health effects.

Methods

This single center study examines the effects of IAP on the fecal infant microbiome in the first year of age and on the T cell phenotype in the first days after birth among 22 infants receiving IAP with penicillin due to maternal GBS colonization and 26 infants not exposed to IAP. The fecal microbiome was analyzed at birth, one month and one year of age through 16S rRNA gene sequencing. Additionally, a T cell phenotyping of peripheral blood was performed between the second and fifth day of age.

Results

At one month, IAP exposed infants had a significantly lower relative abundance of Bifidobacterium longum in fecal samples, an effect which was sustained at one year. In IAP exposed infants we found a proinflammatory T-helper cell profile, characterized by higher IL-17A, RORgt, and TGF-b expression.

Discussion

This study proposes a sustained impact of IAP on the neonatal microbiome and T cell repertoire.

Boosting Immunity Through Nutrition and Gut Health: A Narrative Review on Managing Allergies and Multimorbidity

The increasing global burden of allergic diseases and multimorbidity underscores the urgent need for innovative strategies to strengthen immune health. This review explores the complex relationships among nutrition, gut microbiota, immune regulation, allergic diseases, and multimorbidity. It highlights how targeted nutritional and microbial interventions may influence disease outcomes. Dietary components and microbial metabolites dynamically modulated immune function, highlighting the critical role of the gut-immune-metabolism axis in disease pathogenesis and management. Personalized nutrition, guided by advances in diagnostics such as component-resolved diagnostics, basophil activation tests, and epigenetic biomarkers, allows for precise dietary interventions tailored to individual allergy phenotypes and multimorbidity profiles. The Mediterranean diet, breastfeeding, and microbiota-targeted therapies have emerged as effective strategies to enhance immune resilience, reduce inflammation, and manage allergic reactions. Technological advancements, including artificial intelligence-driven dietary assessments, wearable devices, and mobile applications, have further revolutionized personalized dietary management, enabling real-time, precise nutritional monitoring and intervention. Despite these advances, challenges in implementing personalized nutrition persist, including variability in dietary patterns, cultural and socioeconomic factors, and accessibility concerns. Future research should focus on long-term interventional and longitudinal studies to validate precision nutrition strategies and enhance clinical applicability. This integrative approach, combining nutrition, microbiome science, technology, and personalized healthcare, holds substantial promises for sustainable disease prevention and enhanced immune resilience across diverse populations.

A hierarchy of intestinal antigens instructs the CD4+ T cell receptor repertoire

Intestinal CD4+ T cells that are specific for self-, diet-, or commensal-derived antigens are critical for host tolerance but must also be tightly regulated to prevent aberrant activation and conditions like inflammatory bowel disease (IBD). However, it is unclear how the antigen source and location dictate the intestinal TCR repertoire. Here, we hierarchically classified self-, diet-, or microbiota-dependent TCRs using TCliβ TCRβ transgenic mice. This demonstrated that microbiota had a greater influence than diet on CD4+ T cell responses throughout the intestine at homeostasis. Complex bi-directional interactions between microbes and diet were also observed. In the context of murine colitis as a model of IBD, we showed that antigen-free diet substantially altered the microbiota and associated T cell responses, which ameliorated intestinal inflammation. Collectively, these findings suggest how deconvoluting the gut immune interactome may facilitate identifying primary microbial and dietary drivers of T cell responses during health and disease.

IL-10 sensing by lung interstitial macrophages prevents bacterial dysbiosis-driven pulmonary inflammation and maintains immune homeostasis

Crosstalk between the immune system and the microbiome is critical for maintaining immune homeostasis. Here, we examined this communication and the impact of immune-suppressive IL-10 signaling on pulmonary homeostasis. We found that IL-10 sensing by interstitial macrophages (IMs) is required to prevent spontaneous lung inflammation. Loss of IL-10 signaling in IMs initiated an inflammatory cascade through the activation of classical monocytes and CD4+ T cell subsets, leading to chronic lung inflammation with age. Analyses of antibiotic-treated and germ-free mice established that lung inflammation in the animals lacking IL-10 signaling was triggered by commensal bacteria. 16S rRNA sequencing revealed Delftia acidovorans and Rhodococcus erythropolis as potential drivers of lung inflammation. Intranasal administration of these bacteria or transplantation of human fecal microbiota elicited lung inflammation in gnotobiotic Il10-deficient mice. These findings highlight that IL-10 sensing by IMs contributes to pulmonary homeostasis by preventing lung inflammation caused by commensal dysbiosis.

Butyrate-producing bacteria in pregnancy maintenance: mitigating dysbiosis-induced preterm birth

BACKGROUND

Preterm birth (PTB) is a major contributor to neonatal morbidity, mortality, and long-term health complications. Despite advances in perinatal care, PTB rates remain high, and its multifactorial etiology is not fully understood. Increasing evidence suggests that maternal gut microbiota plays a critical role in pregnancy maintenance, potentially through modulation of immune responses. However, the underlying causal mechanisms remain unclear. We hypothesized that dysbiosis disrupts immune tolerance and promotes PTB, and that butyrate (short-chain fatty acid produced by specific gut bacteria) may counteract this effect by enhancing regulatory T cell (Treg)-mediated immune regulation.

METHODS

We established a dysbiosis-induced PTB mouse model using vancomycin treatment combined with subclinical immune activation via anti-CD3ε antibody. Pregnant mice were fed either a standard or butyrate-enriched diet. Outcomes included gestational length, PTB incidence, live pup rates, and Treg cell levels assessed by flow cytometry. Parallelly, 16S rRNA gene sequencing was performed on fecal samples from 32 pregnant women to compare gut microbial composition between spontaneous PTB and term birth groups. Multivariate logistic regression and correlation analyses were conducted to assess associations with gestational outcomes.

RESULTS

Vancomycin-induced dysbiosis in mice significantly reduced Treg cell populations and increased PTB rates (43.3% in dysbiosis vs. 0% in controls; p < 0.05), while butyrate supplementation reduced PTB incidence (p = 0.03), prolonged gestation (p = 0.01), and restored Treg counts (p < 0.001). In human samples, significant reductions in Lachnospiraceae and Ruminococcaceae, representative butyrate-producing bacteria, were seen in PTB cases. Their combined abundance was independently associated with sPTB risk (p = 0.019) and positively correlated with gestational age (r = 0.59, p < 0.001).

CONCLUSIONS

Our findings demonstrate that maternal dysbiosis increases PTB risk via impaired immune tolerance, and that butyrate supplementation effectively reverses this effect in vivo. Human data support the translational relevance of butyrate-producing microbiota in pregnancy maintenance. These results highlight butyrate as a promising target for dietary interventions aimed at reducing PTB incidence by restoring immune homeostasis. Trial registration Not applicable.

Probiotics and mediterranean diet for breast cancer management and prevention?

The human gut microbiota, a diverse community of beneficial normal flora microorganisms, significantly influences physiological function and the immune response. Various microbiota strains have shown promise in supporting clinical treatment of chronic diseases, including cancer, by potentially providing antioxidative and anti-tumorigenic effects in both in vivo and in vitro studies. Breast cancer, which ranks amongst the top five cancer types common worldwide and particularly in Mediterranean countries, has been showing high incidence and prevalence. In breast cancer, microbiota composition, hormonal dynamics, and dietary choices are believed to play significant roles. Hence, the Mediterranean diet, known for its microbiota-friendly features, emerges as a potential protective factor against breast cancer development, highlighting the potential for personalized dietary strategies in cancer prevention. This comprehensive review highlights the emerging mechanisms by which probiotics support our immune system during different physiological activities. It also discusses their potential role, along with nutrition intervention, in improving essential clinical treatment outcomes in breast cancer patients and survivors, suggesting potential supportive strategies that go hand in hand with clinical strategies. Unfortunately, very little research addresses the possible clinical implications of probiotics and dietary habits on breast cancer, despite the promising results, calling for further studies and actions.

The Relationship Between Gut Microbiota and Recurrent Spontaneous Abortion

Recently, the gut microbiota has been found to be associated with multiple organs and systems in the human body, playing a key role in the occurrence and development of various diseases, such as the gut-brain axis and the gut-liver axis. However, its interaction with miscarriages remains poorly understood. This article reviews the characteristics of gut microbiota and its metabolites in patients with recurrent spontaneous abortion (RSA), the mechanism of gut microbiota inducing RSA, and potential therapeutic strategies. Therefore, it provides a new perspective on the gut microbiota in the pathogenesis and treatment of recurrent abortion, and the prospect of the future research direction of gut microbiota and recurrent abortion is proposed based on existing studies.

Nervous system-gut microbiota-immune system axis: future directions for preventing tumor

Tumor is one of the leading causes of death worldwide. The occurrence and development of tumors are related to multiple systems and factors such as the immune system, gut microbiota, and nervous system. The immune system plays a critical role in tumor development. Studies have also found that the gut microbiota can directly or indirectly affect tumorigenesis and tumor development. With increasing attention on the tumor microenvironment in recent years, the nervous system has emerged as a novel regulator of tumor development. Some tumor therapies based on the nervous system have also been tested in clinical trials. However, the nervous system can not only directly interact with tumor cells but also indirectly affect tumor development through the gut microbiota. The nervous system-mediated gut microbiota can regulate tumorigenesis, growth, invasion, and metastasis through the immune system. Here, we mainly explore the potential effects of the nervous system-gut microbiota-immune system axis on tumorigenesis and tumor development. The effects of the nervous system-gut microbiota-immune system axis on tumors involve the nervous system regulating immune cells through the gut microbiota, which can prevent tumor development. Meanwhile, the direct effects of the gut microbiota on tumors and the regulation of the immune system by the nervous system, which can affect tumor development, are also reviewed.

Short-term exposure to ciprofloxacin and microplastic leads to intrahepatic cholestasis, while long-term exposure decreases energy metabolism and increases the risk of obesity

Microplastics (MPs) and antibiotics are pervasive pollutants that may pose a risk to human health. Studies have shown that both MPs and antibiotics adversely affect lipid metabolism and increase the risk of obesity. However, it remains unclear whether combined exposure to these pollutants intensify the cumulative detrimental effect on obesity and metabolism. This study demonstrated the impact of exposure to polystyrene MPs (PS, 25 nm) and ciprofloxacin (CIP), both individually and combined, for 30 d and 90 d on the hepatic metabolism of male C57BL/6J mice. The results showed that mice exposed to PS and CIP for either 30 d or 90 d exhibited lipid metabolism disorders such as increased body weight, enlarged adipocytes, triglyceride accumulation in the liver, and higher HDL-C. Differentially expressed hepatic proteins were identified via proteomic analysis. The findings indicated that exposure for 30 d caused abnormal bile acid (BA) secretion in the liver and inhibited the BA secretion pathway, which resulted in intrahepatic cholestasis. Furthermore, exposure for 90 d resolved cholestasis and reduced the overall number of differentially expressed proteins. Intestinal pathology revealed more severe damage after exposure for 30 d, while 90 d exposure decreased the adverse effect. Combined CIP and PS exposure caused damage to the organism. However, the adaptive capacity of the organism during prolonged exposure mitigated the damage caused by both, but did not imply the complete eradication of adverse effects. This study found that 90 d exposure to PS and CIP resulted in weight gain, possibly due to changes in the gut flora and suppressed energy metabolism. These results indicated that simultaneous exposure to CIP and PS exacerbated the adverse impact on the liver, causing short-term intrahepatic cholestasis. Prolonged exposure reduced the energy metabolism in the body, exhibiting varied toxicity outcomes and mechanisms at different exposure durations. This study offers novel insights into the effect of MPs and antibiotic CIP exposure on metabolic abnormalities and provides a scientific basis for assessing these risks. It also emphasizes that the adverse effect resulting from 30 d (short-term) toxic exposure may not persist and that long-term chronic toxicity needs warrants.

Intestinal luminal anion transporters and their interplay with gut microbiome and inflammation

The intestine, as a critical interface between the external environment and the internal body, plays a central role in nutrient absorption, immune regulation, and maintaining homeostasis. The intestinal epithelium, composed of specialized epithelial cells, harbors apical anion transporters that primarily mediate the transport of chloride and bicarbonate ions, essential for maintaining electrolyte balance, pH homeostasis, and fluid absorption/secretion. In addition, the intestine hosts a diverse population of gut microbiota that plays a pivotal role in various physiological processes including nutrient metabolism, immune regulation, and maintenance of intestinal barrier integrity, all of which are critical for host gut homeostasis and health. The anion transporters and gut microbiome are intricately interconnected, where alterations in one can trigger changes in the other, leading to compromised barrier integrity and increasing susceptibility to pathophysiological states including gut inflammation. This review focuses on the interplay of key apical anion transporters including Down-Regulated in Adenoma (DRA, SLC26A3), Putative Anion Transporter-1 (PAT1, SLC26A6), and Cystic Fibrosis Transmembrane Conductance Regulator [CFTR, ATP-binding cassette subfamily C member 7 (ABCC7)] with the gut microbiome, barrier integrity, and their relationship to gut inflammation.

Gut Microbiota and Immunoglobulin A Nephropathy: Exploration of Dietary Intervention and Treatment Strategies

Immunoglobulin A nephropathy (IgAN) is a primary glomerular disease characterized by the deposition of IgA. The pathogenesis of it is related to the dysbiosis of gut microbiota. Dysbiosis of gut microbiota influences mucosal immune response and systemic immune system, leading to glycosylation-deficient IgA1 (Gd-IgA1) increasing, which promotes the development of IgAN. Diet plays an important role in regulating gut microbiota and treating IgAN. In this review, we summarize the interplay between gut microbiota and IgAN, and their underlying mechanisms. We also describe the effects of dietary intake on IgAN, as well as the composition of gut microbiota. The progress on IgAN treatment mainly focuses on inhibiting or regulating the immune system. Moreover, therapeutic strategies related to gut microbiota such as dietary intervention, supplement of probiotics and prebiotics, as well as fecal microbiota transplantation (FMT) have shown the possibility of improving IgAN prognosis. Thus, exploration of the gut-kidney axis, the long-term effects of diet and microbiome is necessary to develop more effective treatment strategies.

Exploring the Therapeutic and Gut Microbiota-Modulating Effects of Qingreliangxuefang on IMQ-Induced Psoriasis

Purpose

To investigate the therapeutic and gut microbiota-modulating effects of Qingreliangxuefang (QRLXF) on psoriasis.

Materials and Methods

We used network pharmacology, a computational approach, to identify key bioactive compounds and biological targets, and explored the molecular mechanisms of QRLXF. The effects of QRLXF on keratinocyte proliferation and inflammation were evaluated using a mouse model of psoriasis. Changes in the gut microbiota were analyzed via 16SrDNA sequencing, and T cell subsets were assessed using flow cytometry.

Results

Network pharmacology analysis suggested that QRLXF ameliorated psoriasis by modulating Th17 cell differentiation. Further experiments confirmed the anti-inflammatory effects and relief of psoriatic lesions in IMQ-induced mice. 16SrDNA sequencing revealed significant shifts in the gut microbiota, notably increases in Ligilactobacillus and Lactobacillus genera and decreases in Anaerotruncus, Negativibacillus, Bilophila, and Mucispirillum, suggesting a potential relationship between specific microbiota changes and Th17 cell differentiation.

Conclusion

QRLXF alleviated psoriatic dermatitis by regulating Th17 cell responses and modifying gut microbiota profiles, highlighting its therapeutic potential for psoriasis treatment.

A specific microbial consortium enhances Th1 immunity, improves LCMV viral clearance but aggravates LCMV disease pathology in mice

Anti-viral immunity can vary tremendously from individual to individual but mechanistic understanding is still scarce. Here, we show that a defined, low complex bacterial community (OMM12) but not the general absence of microbes in germ-free mice leads to a more potent immune response compared to the microbiome of specific-pathogen-free (SPF) mice after a systemic viral infection with LCMV Clone-13. Consequently, gnotobiotic mice colonized with OMM12 have more severe LCMV-induced disease pathology but also enhance viral clearance in the intestinal tract. Mechanistically, single-cell RNA sequencing analysis of adoptively transferred virus-specific T helper cells and endogenous T helper cells in the intestinal tract reveal a stronger pro-inflammatory Th1 profile and a more vigorous expansion in OMM12 than SPF mice. Altogether, our work highlights the causative function of the intestinal microbiome for shaping adaptive anti-viral immunity with implications for vaccination strategies and anti-cancer treatment regimens.

Structural characterization of raw and wine-steamed Polygonatum cyrtonema Hua oligosaccharides and their bioactivity on immune regulation via modifying the gut microbiota

Polygonatum cyrtonema Hua (PC) is a traditional Chinese medicine with a long history of use as pharmaceuticals or functional foods. Wine steaming is the main processing method of PC, which changes the structure of polysaccharides and oligosaccharides in PC and enhances biological activities. This study investigated the structural characterization of raw and wine-steamed PC oligosaccharides and the differences in the immunomodulatory effects using cyclophosphamide (CTX)-induced immunosuppression rat model. The oligosaccharides content and molecular weight of PC after wine steaming decreased, the proportion of oligosaccharides in total sugars and the reducing sugars content increased, and the monosaccharides composition of oligosaccharides changed. The raw Polygonatum cyrtonema Hua oligosaccharides (PCCO) and the wine-steamed Polygonatum cyrtonema Hua oligosaccharides (PCWO) exerted regulatory effects on organ index, immunoglobulin G (IgG), complement 3 (C3) spleen and colon tissue morphology, hematopoietic function of immunosuppressive rats treated by cyclophosphamide (CTX). Both PCCO and PCWO significantly regulated and improved the diversity and abundance of gut microbiota in immunosuppressed rats and increased the content of short-chain fatty acids (SCFAs) in the feces of rats, and the regulating effect of PCWO was better than PCCO. Differential microbiota analysis showed that PCWO could promote the proliferation of Bifidobacterium, Bacteroides, Oscillibacter, Roseburia, and Alistipes. In summary, the difference in the structural characteristics of PC oligosaccharides might be the reason for immune enhancement. This study could provide a theoretical basis for clarifying the scientific connotation of wine steaming to enhance the efficacy of PC, and promote the application of wine-steamed PC as an immunomodulator in pharmaceuticals or functional foods.

Effects of Phytosterols on Growth Performance, Serum Indexes, and Fecal Microbiota in Finishing Pigs

Phytosterols (PSs) are widely present in plants, particularly abundant in plant oils and seeds. PSs are reported to have various biological activities, such as lowering cholesterol, alongside antioxidant and antibacterial activities. This research examined the effects of PSs in finishing pigs, including growth performance, serum biochemistry, and fecal bacteria. Two treatment groups (each treatment group consisted of five biological replicates, and each replicate comprised five pigs housed communally) were randomly assigned to the fifty finishing pigs (equally divided by sex) of "Duroc × Landrace × Yorkshire" three-way cross with 79.76 ± 1.29 (kg) body weight. The control group (CON) was given basic food, while the experimental group was given basic food containing 300 mg PS/kg (PS). Dietary PS supplementation markedly raised the levels of average daily feed intake (ADFI) and apparent digestibility of dry matter (DM), crude protein (CP), ether extract (EE), and gross energy (GE) in comparison to the CON (p < 0.05). Additionally, PSs also significantly boosted the concentrations of high-density lipoprotein cholesterol (HDL-C), total protein (TP), catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), immunoglobulin G (IgG), motilin (MTL), and glucagon-like peptide-1 (GLP-1) (p < 0.05), and lowered the lactate dehydrogenase (LDH) level (p < 0.05). Both at the phyla and genus levels, the relative abundance of Firmicutes and Streptococcus increased significantly, and the relative abundance of Acinetobacter decreased significantly when adding phytosterols (p < 0.05). Overall, phytosterols dietary supplementation promotes immunity and antioxidant capacity in finishing pigs and boosts growth performance by improving nutrient digestibility.

Allicin Improves Diet-Induced Nonalcoholic Steatohepatitis and Gut Microbiota Dysbiosis in Mice via the Involvement of the Circadian Clock Gene Rev-erbα

Nonalcoholic Steatohepatitis (NASH) is a progressive liver disease characterized by inflammation and liver damage. Allicin, a bioactive compound derived from garlic, has demonstrated anti-inflammatory and antioxidant properties. This study explores the effects of allicin on NASH and gut microbiota dysbiosis induced by a high-fat, high-fructose diet (HFFD) in mice. Allicin supplementation significantly alleviated hepatic inflammation, improved glucose metabolism, and modulated the circadian rhythm gene Rev-erbα, which plays a critical role in regulating inflammation. The anti-inflammatory effects of allicin were diminished in Si-Rev-erbα-treated HepG2 cells, highlighting the importance of circadian regulation in mediating these effects. Allicin's anti-inflammatory effects were associated with increased levels of short-chain fatty acids (SCFAs) and the restoration of diurnal oscillations in proinflammatory cytokines and gut microbiota composition, particularly in genera, such as Akkermansia, Bacteroidetes, and Lactobacillus. These findings suggest that allicin could be a promising therapeutic approach for managing NASH, liver dysfunction, and related metabolic disorders through the modulation of circadian rhythms and the gut microbiome.

The effectiveness of treatment with probiotics in preventing necrotizing enterocolitis and related mortality: results from an umbrella meta-analysis on meta-analyses of randomized controlled trials

INTRODUCTION

Probiotic supplementation has been proposed as a preventive measure for necrotizing enterocolitis (NEC) in preterm infants. This umbrella meta-analysis assesses the effects of probiotics, including single-strain and multi-strain formulations, on NEC and related mortality.

METHODS

A comprehensive search was conducted in PubMed, Scopus, ISI Web of Science, and Embase for studies up to August 2024. The AMSTAR2 tool assessed the quality of included studies. Meta-analysis studies were selected based on the PICOS framework, focusing on preterm neonates (< 37-week gestation), probiotic supplementation (single-strain or multi-strain), placebo or standard care comparison, and outcomes of NEC and mortality. Pooled relative risks (RR) and odds ratios (OR) with 95% confidence intervals (CI) were calculated using random-effects models.

RESULTS

Overall, 35 eligible studies were included into the study. Twenty-six and 32 probiotic intervention arms used single- and multi-strain probiotics, respectively. The findings revealed that probiotics decreased NEC significantly (ESRR: 0.51; 95% CI: 0.46, 0.55, p < 0.001, and ESOR: 0.59; 95%CI: 0.48, 0.72, P < 0.001), and mortality rate (ESRR: 0.72; 95% CI: 0.68, 0.76, P < 0.001, and ESOR: 0.77; 95%CI: 0.70, 0.84, p < 0.001).

CONCLUSION

The present review suggests that supplementation with probiotics reduced NEC and related mortality. Probiotic supplementation can be recognized as a NEC-preventing approach in preterm and very preterm infants, particularly Multi-strain probiotics.

A Novel Frontier in Gut-Brain Axis Research: The Transplantation of Fecal Microbiota in Neurodegenerative Disorders

The gut-brain axis (GBA) represents a sophisticated bidirectional communication system connecting the central nervous system (CNS) and the gastrointestinal (GI) tract. This interplay occurs primarily through neuronal, immune, and metabolic pathways. Dysbiosis in gut microbiota has been associated with multiple neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS). In recent years, fecal microbiota transplantation (FMT) has gained attention as an innovative therapeutic approach, aiming to restore microbial balance in the gut while influencing neuroinflammatory and neurodegenerative pathways. This review explores the mechanisms by which FMT impacts the gut-brain axis. Key areas of focus include its ability to reduce neuroinflammation, strengthen gut barrier integrity, regulate neurotransmitter production, and reinstate microbial diversity. Both preclinical and clinical studies indicate that FMT can alleviate motor and cognitive deficits in PD and AD, lower neuroinflammatory markers in MS, and enhance respiratory and neuromuscular functions in ALS. Despite these findings, several challenges remain, including donor selection complexities, uncertainties about long-term safety, and inconsistencies in clinical outcomes. Innovations such as synthetic microbial communities, engineered probiotics, and AI-driven analysis of the microbiome hold the potential to improve the precision and effectiveness of FMT in managing neurodegenerative conditions. Although FMT presents considerable promise as a therapeutic development, its widespread application for neurodegenerative diseases requires thorough validation through well-designed, large-scale clinical trials. It is essential to establish standardized protocols, refine donor selection processes, and deepen our understanding of the molecular mechanisms behind its efficacy.

Soluble CTLA-4 regulates immune homeostasis and promotes resolution of inflammation by suppressing type 1 but allowing type 2 immunity

Cytotoxic T-lymphocyte-associated antigen -4 (CTLA-4) is a co-inhibitory receptor that restricts T cell activation. CTLA-4 exists as membrane (mCTLA-4) and soluble (sCTLA-4) forms, but the key producers, kinetics, and functions of sCTLA-4 are unclear. Here, we investigated the roles of sCTLA-4 in immune regulation under non-inflammatory and inflammatory conditions. Effector regulatory T (Treg) cells were the most active sCTLA-4 producers in basal and inflammatory states, with distinct kinetics upon T cell receptor (TCR) stimulation. We generated mice specifically deficient in sCTLA-4 production, which exhibited spontaneous activation of type 1 immune cells and heightened autoantibody/immunoglobulin E (IgE) production. Conversely, mCTLA-4-deficient mice developed severe type 2-skewed autoimmunity. sCTLA-4 blockade of CD80/86 on antigen-presenting cells inhibited T helper (Th)1, but not Th2, differentiation in vitro. In vivo, Treg-produced sCTLA-4, suppressed Th1-mediated experimental colitis, and enhanced wound healing but hampered tumor immunity. Thus, sCTLA-4 is essential for immune homeostasis and controlling type 1 immunity while allowing type 2 immunity to facilitate resolution in inflammatory conditions.

Comparative analyses of the gut microbiome of two sympatric rodent species, Myodes rufocanus and Apodemus peninsulae, in northeast China based on metagenome sequencing

The gut microbiota is integral to an animal's physiology, influencing nutritional metabolism, immune function, and environmental adaptation. Despite the significance of gut microbiota in wild rodents, the Korean field mouse (Apodemus peninsulae) and the gray red-backed vole (Myodes rufocanus) remain understudied. To address this, a metagenomic sequencing analysis of the gut microbiome of these sympatric rodents in northeast China's temperate forests was conducted. Intestinal contents were collected from A. peninsulae and M. rufocanus within the Mudanfeng National Nature Reserve. High-throughput sequencing elucidated the gut microbiome's composition, diversity, and functional pathways. Firmicutes, Bacteroidetes, and Proteobacteria were identified as the dominant phyla, with M. rufocanus showing greater microbiome diversity. Key findings indicated distinct gut bacterial communities between the species, with M. rufocanus having a higher abundance of Proteobacteria. The gut microbiota of A. peninsulae and M. rufocanus differed marginally in functional profiles, specifically in the breakdown of complex carbohydrates, which might reflect their distinct food preferences albeit both being herbivores with a substantial dietary overlap. The investigation further elucidated gut microbiota's contributions to energy metabolism and environmental adaptation mechanisms. This study aligns with information on rodent gut microbiota in literature and highlights the two understudied rodent species, providing comparative data for future studies investigating the role of gut microbiota in wildlife health and ecosystem functioning.

Microbiome alterations in primary Sjögren's syndrome: Regional dysbiosis and microbiome-targeted therapeutic strategies

Primary Sjögren's syndrome (pSS) is a complex autoimmune disease characterized by diverse clinical manifestations. While xerophthalmia and xerostomia are hallmark symptoms, the disease often involves multiple organ systems, including the kidneys, lungs, nervous system, and gastrointestinal tract, leading to systemic morbidity in severe cases. Despite extensive research, the precise pathogenesis of pSS remains unclear, likely involving infectious, hormonal, and genetic factors. Emerging evidence highlights the microbiome as a key contributor to autoimmune diseases, including pSS. Dysbiosis in the oral, ocular, gut, and genital microbiomes plays a critical role in disease onset, progression, and variability. This review summarizes current findings on microbiome alterations in pSS, emphasizing their role in pathogenesis and clinical features, and explores microbiome-targeted therapies. Understanding the role of the microbiome in pSS pathophysiology could advance disease management and inspire targeted therapeutic strategies.

Exploring the role of polysaccharides in mitigating organ damage caused by pesticide-induced toxicity: A systematic review and meta-analysis of in vivo studies

Although polysaccharides have demonstrated potential in alleviating dysbiosis, the overall impact of polysaccharides on minimizing oxidative stress and organ damage in vivo has not been thoroughly investigated. The aim of this study was to investigate the comprehensive effects of polysaccharides in mitigating pesticide toxicity in animal studies, focusing on biomarkers related to oxidative stress, antioxidant activity, kidney injury, lipid profiles, liver function, and the preservation of liver and kidney weights. A systematic search was conducted across nine indexed databases, including PubMed, Cochrane CENTRAL, Taylor & Francis, Scopus, Sage, EBSCO, ProQuest, ScienceDirect, and Google Scholar. Rayyan.ai was used to screen in vivo studies that met the predefined inclusion and exclusion criteria. The quality of the selected in vivo studies was evaluated using SYRCLE's Risk of Bias tool, specifically designed for animal studies. Thirteen randomized animal studies, comprising 330 mice and rats, were included in the analysis. The findings revealed that polysaccharides significantly increased antioxidant levels, including catalase (CAT) (p<0.00001), superoxide dismutase (SOD) (p<0.00001), glutathione peroxidase (GPx) (p<0.00001), and reduced glutathione (GSH) (p<0.00001). Polysaccharides also significantly reduced oxidative stress markers, such as malondialdehyde (MDA) (p<0.00001) and nitric oxide (NO) (p<0.0001), as well as kidney injury biomarkers, including serum creatinine (p<0.00001) and urea (p<0.00001). Additionally, improvements in lipid profiles were observed, with significant reductions in triglycerides (TG) (p=0.04) and total cholesterol (TC) (p<0.00001). However, there were no significant differences in high-density lipoprotein (HDL) (p=0.28) and low-density lipoprotein (LDL) (p=0.32) levels. Polysaccharides significantly alleviate liver biomarkers, including aspartate transaminase (AST) (p<0.0001), alanine transaminase (ALT) (p<0.005), and alkaline phosphatase (ALP) (p<0.0001). Polysaccharides also contributed to the maintenance of liver weight (p=0.009), although no significant differences were observed in kidney weights (p=0.81). The study highlights that polysaccharides exert significant effects in enhancing antioxidant levels, reducing oxidative stress and organ damage biomarkers, and preserving liver weights.

Investigating Polyreactivity of CD4+ T Cells to the Intestinal Microbiota

Antigen-specific recognition of microbiota by T cells enforces tolerance at homeostasis. Conversely, dysbiosis leads to imbalanced T-cell responses, triggering inflammatory and autoimmune diseases. Despite their significance, the identities of immunogenic microbial antigens remain largely enigmatic. Here, we leveraged a sensitive, unbiased, genome-wide screening platform to identify peptides from Akkermansia muciniphila (AKK) and Bacteroides thetaiotaomicron (BT) recognized by CD4+ T cells. The platform is based on screening peptide libraries using an NFAT-fluorescence reporter cell line transduced with a retrovirus encoding an MHC-TCR (MCR) hybrid molecule. We discovered several novel epitopes from AKK and BT. T-cell hybridomas reactive to AKK and BT bacteria demonstrated polyreactivity to microbiota-derived peptides in co-cultures with MCR reporter cells. Steady-state T cells recognized these epitopes in an MHC-restricted fashion. Intriguingly, most of the identified epitopes are broadly conserved within the given phylum and originate from membrane and intracellular proteins. Ex vivo stimulation of CD4+ T cells from mice vaccinated with the identified peptides revealed mono-specific IFN-γ and IL-17 responses. Our work showcases the potential of the MCR system for identifying immunogenic microbial epitopes, providing a valuable resource. Our study facilitates decoding antigen specificity in immune system-bacterial interactions, with applications in understanding microbiome and pathogenic bacterial immunity.

Modulation of Host Immunity by Microbiome-Derived Indole-3-Propionic Acid and Other Bacterial Metabolites

In recent years, we have witnessed a rapidly growing interest in the intricate communications between intestinal microorganisms and the host immune system. Research on the human microbiome is evolving from merely descriptive and correlative studies to a deeper mechanistic understanding of the bidirectional interactions between gut microbiota and the mucosal immune system. Despite numerous challenges, it has become increasingly evident that an imbalance in gut microbiota composition, known as dysbiosis, is associated with the development and progression of various metabolic, immune, cancer, and neurodegenerative disorders. A growing body of evidence highlights the importance of small molecules produced by intestinal commensal bacteria, collectively referred to as gut microbial metabolites. These metabolites serve as crucial diffusible messengers, translating the microbial language to host cells. This review aims to explore the complex and not yet fully understood molecular mechanisms through which microbiota-derived metabolites influence the activity of the immune cells and shape immune reactions in the gut and other organs. Specifically, we will discuss recent research that reveals the close relationship between microbial indole-3-propionic acid (IPA) and mucosal immunity. Furthermore, we will emphasize the beneficial effects of IPA on intestinal inflammation and discuss its potential clinical implications.

The gut microbiome and dietary metabolites in the treatment of renal cell carcinoma

The gut microbiome is interlinked with renal cell carcinoma (RCC) and its response to systemic treatment. Mounting data suggests that certain elements of the gut microbiome may correlate with improved outcomes. New generation sequencing techniques and advanced bioinformatic data curation are accelerating the investigation of specific markers and metabolites that could predict treatment response. A variety of new therapeutic strategies, such as fecal microbiota transplantation, probiotic supplements, and dietary interventions, are currently being developed to modify the gut microbiome and improve anticancer therapies in patients with RCC. This review discusses the preliminary evidence indicating the role of the microbiome in cancer treatment, the techniques and tools necessary for its proper study and some of the current forms with which the microbiome can be modulated to improve patient outcomes.

Microbiota-dependent modulation of intestinal anti-inflammatory CD4+ T cell responses

Barrier organs such as the gastrointestinal tract, lungs, and skin are colonized by diverse microbial strains, including bacteria, viruses, and fungi. These microorganisms, collectively known as the commensal microbiota, play critical roles in maintaining health by defending against pathogens, metabolizing nutrients, and providing essential metabolites. In the gut, commensal-derived antigens are frequently sensed by the intestinal immune system. Maintaining tolerance toward these beneficial microbial species is crucial, as failure to do so can lead to chronic inflammatory conditions like inflammatory bowel disease (IBD) and can even affect systemic immune or metabolic health. The immune system carefully regulates responses to commensals through various mechanisms, including the induction of anti-inflammatory CD4⁺ T cell responses. Foxp3⁺ regulatory T cells (Foxp3+ Tregs) and Type 1 regulatory T cells (Tr1) play a major role in promoting tolerance, as both cell types can produce the anti-inflammatory cytokine IL-10. In addition to these regulatory T cells, effector T cell subsets, such as Th17 cells, also adopt anti-inflammatory functions within the intestine in response to the microbiota. This process of anti-inflammatory CD4+ T cell induction is heavily influenced by the microbiota and their metabolites. Microbial metabolites affect intestinal epithelial cells, promoting the secretion of anti-inflammatory mediators that create a tolerogenic environment. They also modulate intestinal dendritic cells (DCs) and macrophages, inducing a tolerogenic state, and can interact directly with T cells to drive anti-inflammatory CD4⁺ T cell functionality. The disrupted balance of these signals may result in chronic inflammation, with broader implications for systemic health. In this review, we highlight the intricate interplays between commensal microorganisms and the immune system in the gut. We discuss how the microbiota influences the differentiation of commensal-specific anti-inflammatory CD4⁺ T cells, such as Foxp3⁺ Tregs, Tr1 cells, and Th17 cells, and explore the mechanisms through which microbial metabolites modulate these processes. We further discuss the innate signals that prime and commit these cells to an anti-inflammatory fate.

Impact of Schistosoma mansoni Infection on the Gut Microbiome and Hepatitis B Vaccine Immune Response in Fishing Communities of Lake Victoria, Uganda

OBJECTIVE

Schistosoma mansoni (S. mansoni) infection is endemic in Ugandan fishing communities. We investigated its potential impact on Hepatitis B (Hep B) vaccine responses and its role in mediating the association between the gut microbiome and long-term effectiveness of the vaccine.

METHODS

Participants were tested for S. mansoni infections at baseline and received the Hep B vaccine at baseline, month 1, and month 6. Those with infections were treated. Stool samples were collected at baseline and analyzed using 16S rRNA sequencing. The Wilcoxon rank-sum test was used to compare alpha diversity between groups. A linear regression model was applied to estimate the association between one-year Hep B vaccine responses and the baseline gut microbiome by infection status, adjusting for age and sex.

RESULTS

A total of 107 participants were included (44 from the fishing community and 63 from the Kampala community). There was no significant difference in microbiome composition by location or infection status at baseline or discharge. In the linear regression analysis, S. mansoni infection (β = 1.24, p = 0.025) and a higher alpha diversity (β = 0.001, p = 0.07) were associated with higher Hep B vaccine responses, while older age was associated with a lower Hep B vaccine response (β = -0.06, p = 0.0013).

CONCLUSIONS

S. mansoni infection status before vaccination may modify the association between the gut microbiome and Hep B vaccine response. Potential interventions could focus on infection control as well as improving microbiome richness before implementing vaccine programs in fishing communities.

The role of microbial succinate in the pathophysiology of inflammatory bowel disease: mechanisms and therapeutic potential

Inflammatory bowel disease (IBD) is a chronic immune-mediated condition linked to gut microbiota dysbiosis and altered production of bacterial metabolites, including succinate, which is also a key intermediate in human mitochondrial energy metabolism in human cells. Succinate levels in the gut are influenced by microbial community dynamics and cross-feeding interactions, highlighting its dual metabolic and ecological importance. Extracellular succinate acts as a key signaling metabolite linking microbial metabolism to host physiology, with transient rises supporting metabolic regulation but chronic elevations contributing to metabolic disorders and disease progression. Succinate signals through its cognate receptor SUCNR1, which mediates adaptive metabolic responses under normal conditions but drives inflammation and fibrosis when dysregulated. IBD patients display a dysbiotic gut microbiota characterized by an increased prevalence of succinate-producing bacteria, contributing to elevated succinate levels in the gut and circulation. This imbalance drives inflammation, worsens IBD severity, and contributes to complications like Clostridioides difficile infection and fibrosis. Emerging evidence highlights the potential of intestinal and systemic succinate levels as indicators of microbial dysbiosis, with a bidirectional relationship between microbial composition and succinate metabolism. Understanding the factors influencing succinate levels and their interaction with dysbiosis shows promise in the development of therapeutic strategies to restore microbial balance. Approaches such as dietary fiber enrichment, prebiotics, and probiotics to enhance succinate-consuming bacteria, combined with targeted modulation of succinate pathways (e.g. SDH inhibitors, SUCNR1 antagonists), hold promise for mitigating inflammation and improving gut health in IBD.

KLHL25-ACLY module functions as a switch in the fate determination of the differentiation of iTreg/Th17

The differentiation of Th17 and iTreg is tightly associated with fatty acid metabolism. TGFβ1-induced iTreg differentiation from Th0 relies on fatty acid oxidation (FAO), whereas IL-6 with TGFβ1 shifts metabolism to Th17-preferred fatty acid synthesis (FAS). However, how IL-6 reprograms fatty acid metabolism remains unclear. Here, we unveiled that TGFβ1-activated JNK is recruited to the Klhl25 promoter by NF-YA. JNK then phosphorylates histone H3 at Ser10 to activate Klhl25 transcription, leading to the ubiquitination-dependent degradation of ATP-citrate lyase (ACLY) and the switch from FAS to FAO, which supports iTreg generation. Whereas, upon IL-6 signaling, NF-YA is phosphorylated by ERK, losing its DNA binding ability, which shuts off TGFβ1-JNK-mediated Klhl25 transcription and ACLY ubiquitination, thereby increasing FAS and supporting Th17 differentiation. This study demonstrated that KLHL25-ACLY module functions as a switch in response to TGFβ1 and IL-6 signals, playing a decisive role in the fate determination of iTreg/Th17 differentiation.

Gut integrity in intensive care: alterations in host permeability and the microbiome as potential therapeutic targets

BACKGROUND

The gut has long been hypothesized to be the "motor" of critical illness, propagating inflammation and playing a key role in multiple organ dysfunction. However, the exact mechanisms through which impaired gut integrity potentially contribute to worsened clinical outcome remain to be elucidated. Critical elements of gut dysregulation including intestinal hyperpermeability and a perturbed microbiome are now recognized as potential therapeutic targets in critical care.

MAIN BODY

The gut is a finely tuned ecosystem comprising ~ 40 trillion microorganisms, a single cell layer intestinal epithelia that separates the host from the microbiome and its products, and the mucosal immune system that actively communicates in a bidirectional manner. Under basal conditions, these elements cooperate to maintain a finely balanced homeostasis benefitting both the host and its internal microbial community. Tight junctions between adjacent epithelial cells selectively transport essential molecules while preventing translocation of pathogens. However, critical illness disrupts gut barrier function leading to increased gut permeability, epithelial apoptosis, and immune activation. This disruption is further exacerbated by a shift in the microbiome toward a "pathobiome" dominated by pathogenic microbes with increased expression of virulence factors, which intensifies systemic inflammation and accelerates organ dysfunction. Research has highlighted several potential therapeutic targets to restore gut integrity in the host, including the regulation of epithelial cell function, modulation of tight junction proteins, and inhibition of epithelial apoptosis. Additionally, microbiome-targeted therapies, such as prebiotics, probiotics, fecal microbiota transplantation, and selective decontamination of the digestive tract have also been extensively investigated to promote restoration of gut homeostasis in critically ill patients. Future research is needed to validate the potential efficacy of these interventions in clinical settings and to determine if the gut can be targeted in an individualized fashion.

CONCLUSION

Increased gut permeability and a disrupted microbiome are common in critical illness, potentially driving dysregulated systemic inflammation and organ dysfunction. Therapeutic strategies to modulate gut permeability and restore the composition of microbiome hold promise as novel treatments for critically ill patients.

Identification of antigen-presenting cell-T cell interactions driving immune responses to food

The intestinal immune system must concomitantly tolerate food and commensals and protect against pathogens. Antigen-presenting cells (APCs) orchestrate these immune responses by presenting luminal antigens to CD4+ T cells and inducing their differentiation into regulatory (peripheral regulatory T cell) or inflammatory [T helper (Th) cell] subsets. We used a proximity labeling method (LIPSTIC) to identify APCs that presented dietary antigens under tolerizing and inflammatory conditions and to understand cellular mechanisms by which tolerance to food is induced and can be disrupted by infection. Helminth infections disrupted tolerance induction proportionally to the reduction in the ratio between tolerogenic APCs-including migratory dendritic cells (cDC1s) and Rorγt+ APCs-and inflammatory APCs, which were primarily cDC2s. These inflammatory cDC2s expanded by helminth infection did not present dietary antigens, thus avoiding diet-specific Th2 responses.

Intestinal Microbiota and Vaccinations: A Systematic Review of the Literature

Background: Vaccination constitutes a low-cost, safe, and efficient public health measure that can help prevent the spread of infectious diseases and benefit the community. The fact that vaccination effectiveness varies among populations, and that the causes of this are still unclear, indicates that several factors are involved and should be thoroughly examined. The "intestinal microbiota" is the most crucial of these elements. Numerous clinical studies demonstrate the intestinal microbiota's significance in determining the alleged "immunogenicity" and efficacy of vaccines. This systematic review aimed to review all relevant scientific literature and highlight the role of intestinal microbiota in COVID-19, Salmonella typhi, Vibrio cholerae, and rotavirus vaccinations. Materials and Methods: The MESH terms "vaccines" and "microbiota" were used to search the major scientific databases PubMed, SciVerse Scopus, Web of Knowledge, and the Cochrane Central Register of Controlled Clinical Trials. Results: Between February 2024 and October 2024, the analysis was conducted using electronic databases, yielding a total of 235 references. Finally, 24 RCTs were chosen after meeting all inclusion criteria: eight studies of COVID-19, two studies of Salmonella typhi, three studies of Vibrio cholerae, and eleven studies of rotavirus. Only six of these demonstrated good study quality with a Jadad score of three or four. Conclusions: According to the review's results, the intestinal microbiota surely plays a role in vaccinations' enhanced immunogenicity, especially in younger people. As it is still unclear what mechanisms underlie this effect, more research is needed to better understand the role of the intestinal microbiota.

Microbiome functional gene pathways predict cognitive performance in older adults with Alzheimer's disease

Disturbances in the gut microbiome is increasing correlated with neurodegenerative disorders, including Alzheimer's Disease. The microbiome may in fact influence disease pathology in AD by triggering or potentiating systemic and neuroinflammation, thereby driving disease pathology along the "microbiota-gut-brain-axis". Currently, drivers of cognitive decline and symptomatic progression in AD remain unknown and understudied. Changes in gut microbiome composition may offer clues to potential systemic physiologic and neuropathologic changes that contribute to cognitive decline. Here, we recruited a cohort of 260 older adults (age 60+) living in the community and followed them over time, tracking objective measures of cognition, clinical information, and gut microbiomes. Subjects were classified as healthy controls or as having mild cognitive impairment based on cognitive performance. Those with a diagnosis of Alzheimer's Diseases with confirmed using serum biomarkers. Using metagenomic sequencing, we found that relative species abundances correlated well with cognition status (MCI or AD). Furthermore, gene pathways analyses suggest certain microbial metabolic pathways to either be correlated with cognitive decline or maintaining cognitive function. Specifically, genes involved in the urea cycle or production of methionine and cysteine predicted worse cognitive performance. Our study suggests that gut microbiome composition may predict AD cognitive performance.

BT1549 coordinates the in vitro IL-10 inducing activity of Bacteroides thetaiotaomicron

The intestine is home to a complex immune system that is engaged in mutualistic interactions with the microbiome that maintain intestinal homeostasis. A variety of immune-derived anti-inflammatory mediators have been uncovered and shown to be critical for maintaining these beneficial immune-microbiome relationships. Notably, the gut microbiome actively invokes the induction of anti-inflammatory pathways that limit the development of microbiome-targeted inflammatory immune responses. Despite the importance of this microbiome-driven immunomodulation, detailed knowledge of the microbial factors that promote these responses remains limited. We have previously established that the gut symbiont Bacteroides thetaiotaomicron stimulates the production of the anti-inflammatory cytokine IL-10 via soluble factors in a Toll-like receptor 2 (TLR2)-MyD88-dependent manner. Here, using TLR2 activity reporter cell lines, we show that the capacity of B. thetaiotaomicron to stimulate TLR2 activity was not critically dependent on either of the canonical heterodimeric forms of TLR2, TLR2/TLR1, or TLR2/TLR6, that typically mediate its function. Furthermore, biochemical manipulation of B. thetaiotaomicron-conditioned media suggests that IL-10 induction is mediated by a protease-resistant or non-proteogenic factor. We next uncovered that deletion of gene BT1549, a predicted secreted lipoprotein, significantly impaired the capacity of B. thetaiotaomicron to induce IL-10, while complementation in trans restored IL-10 induction, suggesting a role for BT1549 in the immunomodulatory function of B. thetaiotaomicron. Collectively, these data provide molecular insight into the pathways through which B. thetaiotaomicron operates to promote intestinal immune tolerance and symbiosis.

IMPORTANCE

Intestinal homeostasis requires the establishment of peaceful interactions between the gut microbiome and the intestinal immune system. Members of the gut microbiome, like the symbiont Bacteroides thetaiotaomicron, actively induce anti-inflammatory immune responses to maintain mutualistic relationships with the host. Despite the importance of such interactions, the specific microbial factors responsible remain largely unknown. Here, we show that B. thetaiotaomicron, which stimulates Toll-like receptor 2 (TLR2) to drive IL-10 production, can stimulate TLR2 independently of TLR1 or TLR6, the two known TLR that can form heterodimers with TLR2 to mediate TLR2-dependent responses. Furthermore, we show that IL-10 induction is likely mediated by a protease-resistant or non-proteogenic factor, and that this requires gene BT1549, a predicted secreted lipoprotein and peptidase. Collectively, our work provides insight into the molecular dialog through which B. thetaiotaomicron coordinates anti-inflammatory immune responses. This knowledge may facilitate future strategies to promote such responses for therapeutic purposes.

Targeting CD4+ T cells through gut microbiota: therapeutic potential of traditional Chinese medicine in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is an autoimmune disease characterized by chronic relapsing inflammation of the intestinal tract. Gut microbiota (GM) and CD4+T cells are important in the development of IBD. A lot of studies have shown that GM and their metabolites like short-chain fatty acids, bile acids and tryptophan can be involved in the differentiation of CD4+T cells through various mechanisms, which in turn regulate the immune homeostasis of the IBD patients. Therefore, regulating CD4+T cells through GM may be a potential therapeutic direction for the treatment of IBD. Many studies have shown that Traditional Chinese Medicine (TCM) formulas and some herbal extracts can affect CD4+T cell differentiation by regulating GM and its metabolites. In this review, we mainly focus on the role of GM and their metabolites in regulating the differentiation of CD4+T cells and their correlation with IBD. We also summarize the current research progress on the regulation of this process by TCM.